64-66 Mustang QA1 Level 2 Full Vehicle Suspension and Handling Kit, w/ 9 Inch Housing

This Package is Engineered for Total Control

The QA1 Level 2 Full Vehicle Handling Kit is a complete, fully engineered suspension solution designed to work as a unified system rather than a collection of individual parts. Each component is carefully matched to improve handling balance, ride quality, and chassis stability, eliminating the compromises of the factory suspension. With double-adjustable coil-overs, reinforced tubular control arms, and a triangulated 4-link rear suspension, this kit delivers precise steering response, reduced body roll, and improved traction.

At the foundation of this kit in the rear (and the difference between this kit and the other Level 2 Package) is QA1’s high-strength 9″ fabricated rear housing and performance 31 Spline axles, built to handle serious power while maintaining smooth, predictable performance on the street. The result is a classic 1964–1966 Mustang that feels more responsive, more controlled, and far more confident—whether cruising, carving corners, or putting power to the pavement.

Key Level 2 System (with Housing) Features

• Complete front and rear suspension system for 1964–1966 Mustangs

• Double-adjustable front and rear coil-overs (independent compression and rebound tuning)

• Tubular upper and lower control arm package in front for improved steering response

• Front sway bar to reduce body roll and improve control in the corners

• Rear triangulated 4-link suspension to eliminate axle wrap and rear wheel hop

• QA1 9 inch fabricated rear housing with 31-spline alloy axles

• Rated for applications up to 650 horsepower

• Durable black powder-coated finish and all main suspension components

Designed for Performance & Adjustability

This Level 2 kit is designed for drivers who want tunability and balance:

• Ride Height Adjustment

  • Front: Stock to –2″

  • Rear: Stock to –3″

• Double-Adjustable Shocks

  • Fine-tune ride comfort and handling for street or aggressive driving

• Improved Suspension Geometry

  • Better traction, sharper turn-in, and increased stability

Rear Axle & Housing Details

• QA1 fabricated 9″ rear housing

• 3″ OD axle tubes with ¼″ wall thickness

• Big Ford “New Style Torino” bearing housing ends

• 31-spline performance alloy axle package

• 5 x 4.5″ wheel bolt pattern

• Rear housing width: 57-3/8″ (wheel mounting surface to WMS)

Important Note: The third member (center section) is sold separately.

Vehicle Fitment

• Fits: 1964, 1965, and 1966 Ford Mustang (all body styles and models)

• Designed specifically for the classic Mustang unibody chassis

• Compatible only with QA1 9 Inch rear housing and included 4-link system (brackets already installed on housing for 4-Link Installation)

Installation Notes

• All Front suspension components are bolt-on

• Rear Axle Housing Included in this kit has all 4 link Brackets Welded on the housing to make installation more straight-forward

• Welding is required for the rear suspension upper crossmember/support installation to the unibody frame rails 

• Comprehensive hardware and instructions included

Professional installation is recommended for best results.

Technical Specifications

Why Choose the QA1 Level 2 Handling Kit with 9-Inch Housing?

• Complete, matched front and rear suspension system upgrade designed to work together

• All-New Heavy Duty 9-Inch Housing w/ all needed 4 Link Brackets Welded on the housing- Simplifies Installation!

• Modern handling and ride quality for classic Mustangs

• High-strength components capable of supporting high-horsepower builds

• Extensive adjustability to dial in comfort or performance

• Backed by QA1’s reputation for quality and engineering

What Type of Build is this Kit Ideal for?

• Street performance builds

• Pro-touring style Mustangs

• Enthusiasts seeking improved handling without compromising drivability

• Classic Mustang owners planning future power upgrades

Bring modern suspension performance to your 1964–1966 Mustang with the QA1 HK02-FM01RS Level 2 Full Vehicle Handling Kit — engineered for strength, adjustability, and confidence-inspiring handling.